Why are traits acquired during the life-time of an individual not inherited?
Acquired traits are those, people attain during it life- time due to change in environment and on the other hand, inheritance is the transfer of characters as well as variations or information from one generation to the next by the copying of DNA. Traits are acquired during the life- time not inherited because inheritance occurs during the birth of an individual, and traits are acquired when people learn for their future and to make the changes in their work that does not affect the DNA of the germ cells, like in the inherited traits where DNA get affected by the changes. If any mutation occurs in the germ cell it can give rise to the new trait being acquired by the next successive generation.
Outline a project which aims to find the dominant coat colour in dogs.
How is the sex of the child determined in human beings?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
How do Mendel’s experiments show that traits are inherited independently?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Explain how sexual reproduction gives rise to more viable variations than asexual reproduction. How does this affect the evolution of those organisms that reproduce sexually?
Explain the terms analogous and homologous organs with examples.
How do Mendel’s experiments show that traits may be dominant or recessive?
Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?
How does the creation of variations in a species promote survival?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What changes can you make in your habits to become more environment-friendly?
What is the difference between a reflex action and walking?
What is the importance of DNA copying in reproduction?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be –
(a) 1:2 (b) 2:1 (c) 1:4 (d) 4:1
We saw in this chapter that there are four main stakeholders when it comes to forests and wildlife. Which among these should have the authority to decide the management of forest produce? Why do you think so?
How much energy is given to each coulomb of charge passing through a 6 V battery?
Explain the mechanism of the cleaning action of soaps.
How is the process of pollination different from fertilisation?
Why does an aqueous solution of an acid conduct electricity?
What are the advantages and disadvantages of using a solar cooker? Are there places where solar cookers would have limited utility?
How are the lungs designed in human beings to maximise the area for exchange of gases?
What are the advantages of sexual reproduction over asexual reproduction?
Name the sodium compound which is used for softening hard water.